Entry Title: Optimizing the Energy Consumption at Process Plant ZA I and ZA III by Substituting Raw Material in Form of Liquid Ammonia to be Vapor Ammonia

CONCEPT AND IMPLEMENTATION

PT Petrokimia Gresik (PG) is the largest and most comprehensive fertilizer manufacturer in Indonesia, producing fertilizers such as Urea, ZA, SP-36, NPK Phonska, DAP, NPK Kebomas, ZK, and organic fertilizer (Petroganik). ZA (ammonium sulfate) fertilizer is produced from a chemical reaction between sulfuric acid (H2SO4) and ammonia vapor (NH3). Based on licensor original design, the supply of ammonia was liquid phase, which was derived from ammonia storage tank and transferred by the pumping system. Ammonia vaporizer is responsible to vaporize liquid ammonia into vapor with steam as the heating medium, and then vapor ammonia is fed to the saturator (reactor) to produce ZA.

Energy consumption becomes one of the most important parameter on the production both in plant ZA I & III and plant ammonia. Less energy consumed per unit plant means that those plants operate efficiently. PG assembled a project to achieve operating efficiencies with main targets of reducing energy per unit production (kJ/ton) at ZA I & ZA III plant by 35% and at Ammonia plant by 15%.

In order to reduce the energy consumption, ammonia feeding which previously supplied from storage tanks using pump system, will be replaced by ammonia vapor from existing refrigeration unit of ammonia plant. The investment of this project cost USD 96,805.

RESULTS

The significant benefits from implementing this innovative engineering design are:

1. Energy requirement for ammonia evaporation is zero;
2. Energy requirement for liquid ammonia transfer pump is zero; and
3. The consumption of cooling water is decreased.

During the year of 2010 to 2014, the project has significant benefits in saving the energy totaled 342,652 GJ/year, furthermore the utility of steam at ZA vaporizer is converged into zero. Therefore the total amount of steam was decreased to 37.31% (average). Power consumption is also decreased due to the transfer pump of liquid ammonia from the tank to the plant ZA and the fan of cooling tower which are not operated. Moreover, the project provides positive impact in reducing emission of greenhouse gases (CO2), on average, by 12,584 ton/year. Other benefit such as financial savings on average reached USD 4,666,213/year.

PG is very proud that the idea originality of the project was come from its own human resources, as well as the evaluation of production aspect and detail design engineering. It was the pioneer of vapor ammonia delivery directly as feeding to produce ZA fertilizer in Indonesian fertilizer industries and even the world. The use of basic concept was first applied to the plant ZA I/III and now the design will be installed in plant ZA II.

AWARDS

Through this innovation, PG has won several awards such as:

1. ASEAN Outstanding Engineering Achievement Award (Outstanding Engineering Achievement Project category) in the 33rd Conference of ASEAN Federation of Engineering Organisations 2015 held in Penang, Malaysia;
2. Gold Trophy from the National Standardization Agency of Indonesia in SNI Award 2015 in the category of Large Organization in Chemicals and Miscellaneous Sector;
3. First Prize (Gold) Adhi Cipta Rekayasa (Engineering Design) Award from the Institution of Engineers Indonesia on November 2014.

PG also has an impressive record of other achievements such as:

1. First Winner in the category of Energy Management in Industry and Building Structure sub category Special Innovation in Industry from the Ministry of Energy and Mineral Resources on the National Energy Efficient Award Ceremony held on November 24, 2015;
2. Second Runner Up in the category of Energy Management for Large Industry from ASEAN Energy Award 2013;
3. Featured in a documentary film “Energy Management in Industry” broadcasted in the national television by the Ministry of Energy and Mineral Resources in 2014 to promote the successful efforts of Energy Conservation in Indonesia.